Diverse methods have been previously disclosed for transferring materials into cells. The materials being transferred may be, for example, nucleic acid molecules, stains, or chemicals which influence the physiology of the target cell. These methods include biolistic methods. Typically, in biolistics, tungsten or gold particles are coated with the substance to be introduced into the cell and are caused to contact the cell at high velocity. Although various biolistic and biolistic-like methods have been developed, including those that use particles other than tungsten and gold, none has proven totally satisfactory for all purposes.
As used in this application, the term “biologically active substance” means a substance or its precursor or a mixture of thereof that can influence the physiology of a target cell, organism or structure including metabolically active cells. Examples of structures including metabolically active cells include, without limitation, fruit removed from the plant and surgically removed animal organs.
The efficiency of genetic transformation varies widely between organisms and within a given organism based on environmental treatment. Diverse methods have been used to increase the transformation efficiency of organisms. Organisms which have been rendered receptive to genetic transformation are commonly referred to as “competent cells.” There is no agreed upon standard as to the efficiency of transformation which causes a cell to be considered “competent.” No method for making cells competent has proven suitable for all circumstances.
Nanodiamond (ND) particles consist of cubic (or hexagonal) diamond phase in the core of the particles and different functional groups on the particle surface. Reported methods of ND particle synthesis are very diverse. Examples of ND synthesis methods include a gas phase nucleation at ambient pressure, chlorination of carbide material at moderate temperatures, high pressure-high temperature graphite transformation within a shock wave, or carbon condensation during detonation of carbon-containing explosives. However, the “nanodiamond” and “ND” as used in this disclosure embraces particles produced in other manners including manufacturing methods not yet discovered. The term nanodiamond also embraces agglomerates of primary nanodiamond particles. Agglomerate sizes, in principle, can be up to several microns.
For purposes of this document, the term onion-like carbon (OLC) particles is used to refer to nanoparticles such as those disclosed by Kuznetsov et al. (in Russian Patent document 2094370, which is hereby incorporated by reference) which are characterized as layered carbon structures. Such OLC particles are not to be confused with carbon onions. While carbon onions are structures made up of enclosed fullerenes, OLC particles are nano-particles of a different class made up of concentric carbon shells which have one or more defects in one or more of the carbon shells. Several different types of defects have been noted including (holes, unpaired electrons, sp2/sp3 irregularities, etc.). OLC shells can be rounded or elongated and several smaller OLC particles can form agglomerates where the whole agglomerate is sometimes enclosed in a larger graphite-like shell. The term OLC will also be used to refer to such agglomerations of OLC particles. OLC particles have been obtained by annealing of nanodiamonds, but use of this term should not preclude other manufacturing methods including manufacturing methods as yet undiscovered.
Depending on the annealing temperature, OLC particles have one or more structural defects. In OLC particles there can be a combination of sp2/sp3 types of bonding while ideal carbon onions are made of sp2 type shells. Ideal carbon onions are made up of layers of enclosed fullerene molecules of differing sizes (e.g., C60, C240, C540, C960, etc.). An OLC is therefore not, strictly speaking, a caged compound. Usually, but not always, the term “OLC particles” is used in connection with particles having a substantial number of structural defects, however, a single defect may be sufficient to distinguish between carbon onions and OLC particles. The term OLC also embraces agglomerates of OLC particles. When annealing temperature is below approximately 1400-1800K, hybrid structures composed of diamond core surrounded by onion-like carbon shells can be obtained. The term OLC also embraces these hybrid structures.
Carbon nanotubes and carbon nanohorns are each examples of nanostructures which are at least principally composed of carbon in a graphite-like configuration. Nanohorns have a horn-like particle shape. Production of nanohorns has included laser ablation of graphite. However, the term “nanohorn” is taken here to include the same or similar nanostructures made by other manufacturing methods, including manufacturing methods as yet undiscovered. Nanotubes are generally cylindrical in shape. There are multi-walled and single walled nanotubes. Multi-walled nanotubes can be made by standard arc-evaporation. Single walled nanotubes can be made, for example, by addition of metals (e.g., cobalt) to the graphite electrodes or by laser-vaporization of graphite. However, the term “nanotube” is taken here to include the same or similar nanostructures made by other manufacturing methods including manufacturing methods as yet undiscovered.
In this disclosure, the term “nanocarbon” refers to OLC, carbon onions, ND, carbon nanotubes, carbon nanohorns, diamondoids and all other nanoparticles which are composed principally of carbon.
As used in this disclosure, cells of a specified category of living thing includes, without limitation, in vivo cells, cells in culture and cells removed from the whole organism. By way of example, the term “insect cells” would embrace cells in whole insects, cultured cells of cell lines derived from insects, and cells removed from whole insects.